1.1 This document specifies a direct measurement method for characterizing the surface roughness of the rail and wheel associated with rolling noise ("acoustic roughness"), in the form of a one-third octave band spectrum.
This document describes a method for:
a) selecting measuring positions along a track or selecting wheels of a vehicle;
b) selecting lateral positions for measurements;
c) the data acquisition procedure;
d) measurement data processing in order to estimate a set of one-third octave band roughness spectra;
e) presentation of this estimate for comparison with limits of acoustic roughness;
f) comparison with a given upper limit in terms of a one-third octave band wavelength spectrum;
g) the measuring system requirements.
1.2 It is applicable to the:
a) compliance testing of reference track sections in relation to the acceptance test for noise emitted by railway vehicles;
b) performance testing of track sections in relation to noise emitted by railway vehicles;
c) acceptance of the running surface condition only in the case where the acoustic roughness is the acceptance criterion;
d) assessment of the wheel surface condition as an input for the acoustic acceptance of brake blocks;
e) assessment of the wheel and rail roughness as input to the calculation of combined wheel rail roughness;
f) diagnosis of wheel-rail noise issues for specific tracks or wheels;
g) assessment of the wheel and rail roughness as input to rolling noise modelling;
h) assessment of the wheel and rail roughness as input to noise source separation methods.
1.3 It is not applicable to the:
a) measurement of roughness (rail roughness, wheel roughness or combined roughness) using an indirect method;
b) analysis of the effect of wheel-rail interaction, such as a “contact filter”;
c) approval of rail and wheel reprofiling, including rail grinding operations, except for those where the acoustic roughness is specifically the approval criterion (and not the grinding quality criteri ...